Is there any #Gnome extension which lets you set any key combination (keyboard shortcut) to run any pre-defined command you set up?
Yes, I've tried searching https://extensions.gnome.org
Edit: No extension needed, thank you @gnomelibre!
You don't really need an extension for that. In Settings, Keyboard, Keyboard Shortcuts, View and customize shotcuts, Custom shortcuts… you can define the shortcut of your choice and associate it with a command.
@gnomelibre Oh shit, yes! Thank you! :D